In Reply.—Drs Green and Kane correctly pointed out that differences in sleep patterns are possible sources of variance in TSH response to protirelin. They hypothesized that the blunted TSH response to protirelin in manic patients compared with normal controls and patients with schizophrenic psychosis that we reported may be an artifact of differences in sleep onset. This hypothesis is based on two assumptions.First, they assumed that increased TSH release after delay of sleep onset that has been reported in one study can result in a blunted TSH response to protirelin. Second, they assumed that the delay in sleep onset is significantly greater in mania than in schizophrenic psychosis. The first assumption could be tested